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低气压环境对混凝土含气量及气泡稳定性的影响

DOI: 10.14062/j.issn.0454-5648.2015.08.09

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Abstract:

通过低气压试验箱模拟高原不同海拔地区气压环境,研究了低气压环境对引气混凝土含气量及气泡稳定性的影响。结果表明环境气压的降低能够显著削弱引气剂的引气能力,混凝土含气量随环境气压降低呈线性减少,当环境气压降低至50kPa时,混凝土含气量比常压环境下降低约28%~52%。低气压环境使引气混凝土气泡稳定性变差,在搅拌结束50~55min内,低压引气混凝土含气量经时损失较大,且气泡间距系数明显增大;延长振捣时间会使低压引气混凝土损失更多气泡,从而导致含气量降低幅度以及间距系数的增大程度均大于常压引气混凝土。

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